Oil Level Fault

[Hakkera]

Looking at a car at the minute which has an oil level light that intermittently comes on. Speaking to the owner, he's changed both the top 'check' unit and the sensor itself to no avail. Worth noting that the oil level is fine, and it doesn't look particularly sludge-y.

This leads me to the concept that it's a wiring fault. How much of a PITA am I looking at to get this sorted?

Thanks!

[daimlerman]

Usual problem is a sticky sensor,remove and soak it in petrol.

[Hakkera]

That's certainly the first thing I'd try. That and dropping the sump pan and cleaning the gunk out of it. (Presuming this isn't an engine out job on an M30)

You'd have hoped a replacement sensor would be sorted from when he put it in though, no?

[daimlerman]

You assume the guy has fitted a new sensor,or have you seen the bill?

[steve_k]

just buy a replacement sensor & replace it for peace of mind & it should solve the problem, most of the time the O ring on the sensor has gone off.

[Hakkera]

He was getting the same issue on the M20 engine he had in there beforehand.

You do, of course make a valid point. And if that's the case, I'd be a happy chappy. I just want to know the worst case scenario, so I can budget for it and appropriately knock him down on price.

[steve_k]

worst case is an on going oil leak, although it could be hiding a far worse problem like an oil pump thats on its way out, thats all i can think of.

[Hakkera]

That's true enough - I viewed the car for about two hours though and drove it on a decent test drive during which time I didn't notice any oil leaking on the floor or anywhere visible when wiggling underneath the engine.

Would a dead oil pump not produce an oil pressure light, rather than a level light?

[steve_k]

A dead oil pump is a dead engine, sounds like its the oil pressure sensor that's on its way, get that changed & that should sort it.

[daimlerman]

A dead oil pump is a dead engine, sounds like its the oil pressure sensor that's on its way, get that changed & that should sort it.

The OP is refering to the oil level light in the check panel,I believe!

[Hakkera]

You are correct.

[steve_k]

A dead oil pump is a dead engine, sounds like its the oil pressure sensor that's on its way, get that changed & that should sort it.

The OP is refering to the oil level light in the check panel,I believe!

sorry my mistake

[Brianmoooore]

Wiring fault is very unlikely. The only place that is remotely likely to give trouble is the plug and socket near the sensor itself.
Is it the early simple level sensor, or the more sophisticated later one which measures static and dynamic level? (How many pins in the plug?).
How enthusiastic is his driving style? Level has to be near full to keep the light off if throwing the car around.

[Hakkera]

sorry my mistake

Not at all, appreciate your efforts.

I'll have to go on the hunt next time I'm viewing the car for the number of pins. The base car is an '88 325is, but I don't know if it could be calculated on age and model? You may well be on to something here though, this connector would be common to both cars if it were the car-side of it that were defective. Though you would think he would have checked this before changing the sensor & the check panel.

I drove the car, so I've little idea quite how enthusiastic he was with his driving. Considering he performed the M30B35 swap though, one could presume it would be reasonably enthusiastic.

The light came on on the test drive, during which he wasn't with me, so I pulled over and checked the oil and found it to be sat quite comfortably just under the higher marker.

[daimlerman]

The light came on on the test drive, during which he wasn't with me, so I pulled over and checked the oil and found it to be sat quite comfortably just under the higher marker.

This is not unusual,oil level needs to be on the upper mark for the light to stay out,I know it sounds daft,but this is a BMW!